pinctrl: single: fix error return code in pcs_parse_one_pinctrl_entry()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Introduced by commit 9dddb4df
(pinctrl: single: support generic pinconf)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-single.c

@@ -1166,7 +1166,8 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	(*map)->data.mux.function = np->name;
 
 	if (pcs->is_pinconf) {
-		if (pcs_parse_pinconf(pcs, np, function, map))
+		res = pcs_parse_pinconf(pcs, np, function, map);
+		if (res)
 			goto free_pingroups;
 		*num_maps = 2;
 	} else {